//1.记得要将头文件加上
#include <stdio.h>
//----------------

int sum = 0;
void diaoyong(int p[],int temp,int shu)
{
	if (p[0] == 0)
	{
	    return;
	}
	if (shu == 4)
	{
	    return;
	}

	p[temp] = shu;
	if (temp == 4)
	{
	    sum++;
	    return;
	}
	for (int i = 0; i <= 9; i++)
	{
	    diaoyong(p, temp + 1, i);
	}
}


int main()
{
	int p[5];
	for (int i = 1; i <= 9; i++)
	{
	     diaoyong(p, 0, i);
	}
	printf("%d", sum);
	return 0;
}